The interactions in aqueous solution of electrophiles, particularly heavy metal complexes, with nucleic acid constituents and polynuculeotides are being studied, primarily by Raman difference spectroscopy augmented by Fourier transform infrared and 1H nmr spectroscopy. The effect of polynucleotide secondary structure on the binding sites and extent of reaction is being examined with the substitutionally labile (H3CHgOH2) ion and the inert (PtCl2(NH3)2) and (Pt(OH2)2(NH3)2)2 ion. For these comparisons, the structureless polynucleotides poly (rU) and poly (rI) and the structured poly (rC), poly (rA), poly (rG), poly (rA) poly (rU) and poly (rG) poly (rC) are being employed. The sensitivity of Raman spectroscopy in the detection of phosphate binding is being evaluated by the determination of crystal spectra of (enPtCMP) 2H2O, a compound known to have platinum coordinated to phosphate. Solution spectra for this system also are being determined for comparison with the crystal spectra. Raman spectrophotometric titrations of purified calf thymus DNA with labile (H3CHgOH2) ion and inert (PtCl2(NH3)2) are being studied to understand the binding reactions and denaturing effects of these two metal complexes.